(a) Except in cases instituted by the United States by information, or complaint of information upon seizures for any breach of the revenue, navigation, or other laws of the United States, stipulations or bonds in admiralty and maritime actions need not be under seal and may be executed on behalf of the stipulator or obligor by his/her/its agent or counsel. Stipulations for costs with corporate surety need not be signed or executed by the party, but may be signed on his/her/its behalf by his/her/its agent or counsel, and shall be sufficient in any event if executed only by the surety approved by the court.
(b) If, before or after commencement of suit, the arresting, attaching or garnishing party accepts any written undertaking to respond on behalf of the vessel or other property sued in return for foregoing its arrest or for stipulating to the release of such vessel or other property, the undertaking shall be filed, shall become the res in place of the vessel or other property sued and shall be deemed the subject referred to when any pleading, order or judgment in the action refers to the vessel or other property. The preceding shall apply to any such undertaking, subject to its own terms, whether or not it has been approved by a judge or the clerk.